The classic porcelain chandelier switch goes to a chandelier with two garlands of lights. So you can turn on only half the lamp if you want with a chandelier switch or you can control two completely different lamps in the room with the same switch.

The chronometer switch is controlled by a porcelain knob. The first turn turns A on, the second turns B on, the third turns A off and the fourth turns B off. The knob can be turned in any direction.